In general, a display system includes a display module and a display control device for controlling the display module. The display module includes pixels, which are arranged in a matrix, and a drive circuit for driving the pixels.
Such pixels are used for FPDs (Flat Panel Display) such as LCDs (Liquid Crystal Display), PDPs (Plasma Display Panel), EL (Electroluminescence) displays, and FEDs (Field Emission Display). Since FPDs can be made thinner and lighter than conventional CRTs (Cathode Ray Tube), the FPDs are used for the majority of display devices in recent years.
On the other hand, the display control device transmits, to the drive circuit of the display module, (i) an image signal and (ii) various control signals for driving the pixels. This causes the drive circuit to carry out a scan process in which the image signal is converted to an image. Then, the display module displays the image based on the image signal.
Recently, along with an increase in the resolution of display modules and with the application of the display modules to portable information devices, there are demands for a reduction in electric power consumption of the display modules. Under such circumstances, a technology disclosed in Patent Literature 1 is proposed.
A display device of Patent Literature 1 is configured such that (i) scanning periods and non-scanning periods are provided and (ii) a control IC receives prevents a gate driver and a source driver from receiving any signals except for gate start pulse signals during the non-scanning periods. This makes it unnecessary to operate logic circuits inside the gate driver and the source driver during the non-scanning periods, and therefore allows a reduction in electric power consumption. Patent Literature 1 further discloses configuring the display device such that it is possible to set a plurality of pausing periods (during which a scan process is paused) according to each type of scanning periods (during which the scan process is carried out).
In addition, as a technology for reducing electric power consumption, there is a known technology in which, in a case where an image displayed on a display module remains unchanged, communication between a display control device and the display module is temporarily suspended. Specifically, the display control device is temporarily suspended from supplying an image signal to the display module. Note that in such a case, a display module typically retains an image, which is displayed on a display, by refreshing the image with the use of an image signal stored in a frame memory which is included in the display module.